Localization in periodically modulated speckle potentials

Disorder in a 1D quantum lattice induces Anderson localization of the eigenstates and drastically alters transport properties of the lattice. In the original Anderson model, the addition of a periodic driving increases, in a certain range of the driving's frequency and amplitude, localization length of the appearing Floquet eigenstates. We go beyond the uncorrelated disorder case and address the experimentally relevant situation when spatial correlations are present in the lattice potential. Their presence induces the creation of an effective mobility edge in the energy spectrum of the system. We find that a slow driving leads to resonant hybridization of the Floquet states, by increasing both the participation numbers and effective widths of the states in the strongly localized band and decreasing values of these characteristics for the states in the quasi-extended band. Strong driving homogenizes the bands, so that the Floquet states loose compactness and tend to be spatially smeared. In the basis of the stationary Hamiltonian, these states retain localization in terms of participation number but become de-localized and spectrum-wide in term of their effective widths. Signatures of thermalization are also observed.Comment: 6 pages, 3 figure

Disentangling age-dependent DNA methylation: deterministic, stochastic, and nonlinear

DNA methylation variability arises due to concurrent genetic and environmental influences. Each of them is a mixture of regular and noisy sources, whose relative contribution has not been satisfactorily understood yet. We conduct a systematic assessment of the age-dependent methylation by the signal-to-noise ratio and identify a wealth of "deterministic" CpG probes (about 90%), whose methylation variability likely originates due to genetic and general environmental factors. The remaining 10% of "stochastic" CpG probes are arguably governed by the biological noise or incidental environmental factors. Investigating the mathematical functional relationship between methylation levels and variability, we find that in about 90% of the age-associated differentially methylated positions, the variability changes as the square of the methylation level, whereas in the most of the remaining cases the dependence is linear. Furthermore, we demonstrate that the methylation level itself in more than 15% cases varies nonlinearly with age (according to the power law), in contrast to the previously assumed linear changes. Our findings present ample evidence of the ubiquity of strong DNA methylation regulation, resulting in the individual age-dependent and nonlinear methylation trajectories, whose divergence explains the cross-sectional variability. It may also serve a basis for constructing novel nonlinear epigenetic clocks

Surface texturing of steel by femtosecond laser and accompanying structure/ phase transformations

Topography, structure, and phase composition of surface layers of AISI 321 stainless steel textured by 1030-nm 320-fs-laser pulses were studied by scanning electron microscopy and X-ray diffraction analysis. Variation in single-pulse fluence and the number of pulses was found to change the laser-produced surface texture from onedimensional quasi-periodic nanograting to microrelief of various roughnes

Polypropylene suture material with anti-inflammatory action

© 2018, Iran Polymer and Petrochemical Institute. Polypropylene (PP) monofilament threads are widely used as surging sutures. Functionalization of their surface to impart new properties is of great importance and interest for medicine. This work provides an efficient approach for chemical activation of PP surface followed by anchoring of anti-inflammatory materials (aspirin and indomethacin). Two chemical routes for activation of PP surface and two anti-inflammatory substances were combined, giving a set of four different functionalized threads. Efficiency in terms of anti-inflammatory action of resultant hybrid materials was proved by ligation of wounds made along the spine of mice with further monitoring of inflammation process. In vivo test on mice showed the best healing of surgical skin wounds by means of suture activated by 45% H2O2 solution in the presence of FeSO4 as catalyst at 60 °C for 2 h, which was then modified with aspirin. Plasma interleukin measurement and histological section experiment were performed to prove the efficiency of the threads used for tissue connection. Highest healing efficiency of the suture is obviously explained by higher containment of anti-inflammatory substance anchored on PP surface. The work provides data on a cheap and easy implementation method for novel hybrid materials in medical applications that are able to perform accurately on surgical intervention sites

Influence of the Mo₁₀Ni₃C₃B phase on the hardness and fracture toughness of Mo-Ni-C-B cermet: experimental and theoretical study

We obtained the decreasing of hardness and comparable values of the fracture toughness of Mo₂NiB₂‑Ni cermets due to the formation of Mo₁₀Ni₃C3B phase. To understand the effect of the Mo₁₀Ni₃C₃B phase on the mechanical properties of the cermet, first-principles calculations were applied to investigate the elastic, electronic, and thermodynamic properties of this phas

A Practically-Oriented Approach in Training University Specialists Based on the Application of Modern Technologies

Статья посвящена проблемам практико-ориентированности в подготовке специалистов вуза. В современных условиях рынка успешно функционировать и динамично развиваться могут только те высшие учебные заведения, которые уделяют пристальное внимание вопросам организации производственной практики студентов. Особое внимание уделяется работе по совершенствованию подходов к организации производственной практики и системы взаимодействия с работодателями в вузе.The gist of this article boils down to the problems of practice-oriented training of university specialists. In modern market conditions, only those higher educational institutions that pay close attention to the organization of students' practical training can successfully function and develop dynamically. Particular attention is paid to work on improving approaches to the organization of industrial practice and the system of interaction with employers at the university

ANALYSIS OF CULTURAL EXCHANGE BETWEEN RUSSIAN AND FOREIGN STUDENTS

В статье показаны особенности культурного обмена между студентами разных стран. Представлены результаты интервью российских студентов, проходивших обучение за границей, а также иностранцев, получающих образование в России. Выделены культурные практики, преобладающие в молодежной среде, обозначено влияние образовательного процесса на восприятие студентами культуры других стран.The article shows the peculiarities of cultural exchange between students from diff erent countries. The results of interviews were conducted with Russian students who studied abroad, as well as with foreign students receiving education in Russia, are described. The cultural practices prevailing in the student environment are highlighted, and the infl uence of educational institutions on the perception of the country’s culture among students is also indicated

Biosynthesis of extracellular guanyl-specific ribonuclease by Bacillus circulans

Biosynthesis of extracellular alkaline guanyl-specific RNase by Bacillus circulans (RNase Bci) was studied. Synthesis of the enzyme by the culture started in the late exponential phase and was inhibited by inorganic phosphate and glucose, in contrast to the biosynthesis of its structural and functional homologue, RNase Ba (barnase) of B. amyloliquefaciens. It is suggested that differences in the regulation of the biosynthesis of RNases Bci and Ba are related to different structures of their gene promoters. © 1998 MAHK Hayka/Interperiodica Publishing

Biosynthesis of extracellular guanyl-specific ribonuclease by bacillus circulans

Biosynthesis of extracellular alkaline guanyl-specific RNase by Bacillus circulans (RNase Bei) was studied. Synthesis of the enzyme by the culture started in the late exponential phase and was inhibited by inorganic phosphate and glucose, in contrast to the biosynthesis of its structural and functional homologue, RNase Ba (barnase) of B. amyloliquefaciens. It is suggested that differences in the regulation of the biosynthesis of RNases Bei and Ba are related to different structures of their gene promoters